ex boyfriend

okay sooo ive been dating a new guy for almost 2 years .. but occasionally i think of my ex and check on his facebook. ? is this wrong of me? i tried blocking him but i cant do it for long. he was controlling and crazy and a man whore. but somehow i fell in love with him. i dont know why i think about him . im with a new guy who treats me better then ever and i love him more than anything and i wanna be with him . is this wrong of me to think about him ?